The present invention relates to a liquid jet recording substrate, a liquid jet recording head using the substrate and a recording apparatus using the recording head, more particularly to the substrate, head and apparatus wherein an electrothermal transducer for producing thermal energy is used to produce the energy for ejecting recording liquid.
The recording system in which the liquid is ejected using the thermal energy is particularly noted in recent years, which is disclosed in U.S. Pat. Nos. 4,723,129 and 4,740,796. The recording system is advantageous, inter alia, in its quick response to the recording electric signal and in its small size due to high density arrangement of the ejecting elements.
A further development of this recording system is disclosed in U.S. Pat. No. 4,719,472 in which the liquid is pre-heated to a predetermined temperature to improve the recording. To accomplish this, the liquid reservoir is provided with a temperature sensor and a heater. The purpose is to regulate the viscosity of the liquid.
As another development, U.S. Pat. No. 4,550,327 discloses a recording head wherein plural thermal energy generating elements are arranged in a predetermined direction and wherein a sensor is provided to discriminate presence and absence of the liquid in each of the liquid passages having the thermal energy generating elements. The purpose is not concerned with the thermal problem, but is known as the system including plural elements and plural sensors. However, this suppresses more or less the advantage of the recording system (small size) due to the necessity of enlarging the liquid passage width.
Accordingly, a recording system wherein the advantage of the small size with high density is maintained, and the state of the recording substrate or the recording head is quickly detected or discriminated, is highly desired.
In the liquid jet recording substrate provided with plural thermal energy producing elements, non-uniform temperature distribution or localized high temperature portion may occur. However, this has not been taken account, and therefore, occurrences of ejection failure leads to abnormal temperature rise with the possible result of physical deformation of the structure around the substrate, made of organic material.
In the conventional systems, the temperature sensor and the heater are separately mounted with the result of increased manufacturing steps and cost. In addition, the temperature control in the conventional system is possible with a certain accuracy as long as the overall temperature of the whole recording head. However, the number of experiments and investigations carried out by the inventors have revealed that after continued recording operations, a temperature gradient is produced in the substrate, so that the quality of the recorded image is degraded. It has been difficult in the conventional system to continue good recording when the temperature gradient is produced.
Accordingly, it is a principal object of the present invention to provide a liquid jet recording substrate, a recording head and apparatus using the same wherein temperature detection is performed with high accuracy and with good response.
It is another object of the present invention to provide a low cost liquid jet recording substrate and the liquid jet recording head and apparatus using the same wherein the problem arising from the temperature gradient produced in the substrate are solved and wherein the temperature detection and temperature control can be performed with high accuracy and with quick response.
It is as yet further object of the present invention to provide a liquid jet recording substrate, and a liquid jet recording head and apparatus wherein a temperature detecting element and a temperature keeping heating element are produced on the substrate through the same film deposition process which is used in the production of an ejection energy producing elements (electrothermal transducers), so that the manufacturing cost is reduced, that they can be closely disposed and that the temperature control can be performed with high accuracy and with quick response.
According to various aspects of the present invention:
(1) A substrate for liquid ejection, comprising: a built-in energy generating element for generating thermal energy; a built-in electrode wiring portion for supplying an electric signal to said energy generating element; and a built-in temperature detecting element for detecting a temperature of said substrate:
(2) A substrate as defined in Paragraph (1), wherein said temperature detecting element is made, at least partly, of a material substantially the same as a material at least partly forming said energy generating element or said electrode wiring portion:
(3) A substrate as defined in Paragraph (1) or (2), wherein said substrate includes a region wherein a plurality of such energy generating elements are disposed in the form of an array, and wherein said temperature detecting element is disposed adjacent each longitudinal end of the array:
(4) A substrate as defined in Paragraph (3), further comprising a heater for heating said substrate provided adjacent said each end, and wherein temperature control is effected using a combination of said temperature detecting element and said substrate heating heater adjacent one of the ends, and using a combination of said temperature detecting element and said substrate heating heater adjacent the other end:
(5) A substrate as defined in Paragraph (4), further comprising a built-in common electric line electrically connected to said temperature detecting element and to said substrate heating heater:
(6) A substrate as defined in Paragraph (1), wherein said temperature detecting element is in the form of a diode temperature sensor comprising plural diodes connected in series, each of which is of substantially the same structure as a switching diode contained in said wiring portion:
(7) A substrate as defined in Paragraph (3), wherein at least a part of each of said temperature sensing element is on an extension of the array:
(8) A substrate as defined in Paragraph (7), wherein said substrate includes a region wherein a plurality of switching element are disposed for selectively driving the plural energy generating elements, a region wherein matrix wiring is disposed between said energy generating element disposed area and said switching element disposed area, and substrate heating heaters disposed adjacent each of end portions of said matrix wiring portion:
(9) A substrate as defined in Paragraph (8), wherein said temperature detecting element is formed using a silicon base member, and said substrate further comprising two electrically insulative layers, wherein said substrate heating heater is formed between extensions of respective electrically insulating layers:
(10) A liquid jet recording head comprising the substrate defined in Paragraph (9) comprising: a common ink chamber for accommodating ink, formed on said substrate, ink passages, corresponding to the respective energy generating elements, for maintaining the ink supplied from said common chamber and ejection outlets through which the ink is ejected for recording; wherein an upper portion at least one of said temperature detecting elements and said substrate heating heaters is outside said common ink chamber and outside an ink maintaining region of said ink passages:
(11) A recording head as defined in Paragrah (10), wherein a part of said matrix wiring portion is disposed on a lower one of said electrically insulating layers adjacent said substrate heating heaters:
(12) An ink jet recording apparatus, to which the recording head as defined in Paragraph (10) is detachably mountable, comprising electrical connection and temperature control means for effecting temperature control using a combination of said temperature detecting element and said substrate heating heater adjacent one of the ends, and for effecting a temperature control using a combination of said temperature detecting element and said substrate heating heater at the other end:
(13) An ink jet recording apparatus to which the recording head as defined in Paragraph (9) is detachably mountable, wherein said common ink chamber has an ink containing portion extending to a neighborhood of boundary between said matrix wiring region and said switching element disposed region and before said switching element disposed region:
(14) An ink jet recording apparatus usable with a recording head containing the substrate as defined in Paragraph (1), comprising recovery means for improving ink ejecting function of the recording head and control means for operating said recovery means in accordance with an output of said temperature detecting element:
(15) A recording head, comprising: a substrate including a built-in energy generating element for generating thermal energy for liquid ejection and electrode wiring portion for supplying an electric signal to said energy generating element; a function element associated with a temperature of said substrate, wherein said function element is also a built-in element of said substrate; a common chamber for containing ink on said substrate, an ink passage for maintaining the ink supplied from said common chamber and corresponding to said energy generating element, and an ink ejection outlet through which the ink is ejected for recording; wherein an upper portion of said function element is outside the common chamber and outside an ink maintaining portion of said passage:
(16) A recording head as defined in Paragraph (15), wherein said function element is made, at least partly, of a material which is substantially the same as a material constituting at least partly said energy generating element or said electrode wiring portion:
(17) A liquid jet recording apparatus, comprising: a plurality of heat generating elements for producing thermal energy to eject recording liquid; heating means provided in a recording head to heat said recording head; and control means for selectively actuating said heat generating elements to produce such heat as not to eject the liquid, so as to control a temperature distribution of the recording head: AND
(18) A liquid jet recording apparatus, comprising: a plurality of heat generating elements for producing thermal energy to eject recording liquid; and means for selectively actuating said heat generating elements to produce such heat as not to eject the liquid, so as to control a temperature distribution in the head, and for heating the recording head when a main switch of said apparatus is closed and/or when a recording starting signal is produced:
are provided.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.